The present invention relates to a dental endosseous implant.
It is known that dental endosseous implants are typically employed when it is necessary to carry out replacement of the whole root of a tooth that has reached a too high degree of decay and therefore is no longer capable of accomplishing its task.
Dental endosseous implants presently available on the market substantially consist of two different typologies.
A first type of endosseous implant, commonly known as buried implant, involves use of cylindrical elements of different sizes possibly provided with a surface working to promote anchoring of same to the bone of the patient""s upper jaw (or maxilla) or lower jaw (or mandible).
These cylindrical elements are fitted into appropriate cavities to be drilled by a dentist at the point of the upper or lower jaw where the implant is to be installed. Practically, the dentist carries out opening of the mucous membrane for making a well in the patient""s bone of substantially the same diameter as that of the cylinder to be fitted, then goes on fitting the implant and reclosing the mucous membrane.
Afterwards, a wait period of about 6-7 months is required to enable fresh growing of the osseous tissue that, by penetrating into the ravines provided in the cylindrical body surface, causes stabilization of said body with which said osseous tissue will form a single unit.
Once the cylindrical implant has become closely and firmly joined with the upper or lower jaws, anchoring to an end portion of said implant is made possible in order to carry out engagement of an outer structure or stump which, in turn, is adapted to receive an appropriate crown that will define the shape of an artificial tooth.
This type of implants has been widespread on the market; presently, buried implants of different shapes and sizes are available that are able to meet a variety of requirements of anatomical nature that patients may have.
In spite of the great success reached on the market by buried implants, they however have some important drawbacks.
Firstly, as briefly pointed out herebefore, typical times for setting up a buried implant are relatively long. Clearly, this is very troublesome for a patient, in particular if the osseous tissue has difficulties in regenerating and therefore the implant does not stabilize in the oral cavity.
A further drawback, as can be easily understood, is represented by the necessity to drill wells or holes for engagement of the cylindrical element in the patient""s upper or lower jaws, the diametrical sizes of which must be the same as, or slightly bigger than those of said element to be fitted. In particular, the cylindrical elements used typically have a diameter of about 5 mm and therefore the diameter of the cavities formed in the patient""s osseous tissue must be the same. Obviously, when installation of several implants is required or even a complete replacement of many roots, a great amount of osseous tissue is to be removed which will be a trauma for the subject submitted to this treatment.
In addition to the above drawbacks, it is also to be noted that, due to the intrinsic stiffness of the buried implants and the impossibility of carrying out deformations on the same once they have been installed, availability of a great number of implant models is made necessary for meeting all possible functional requirements.
In conclusion, it appears from the above that although buried implants require a relatively simple installation process, they however have a poor capability of being personalized upon the dentist""s action, when applied, and are very traumatic for the patient both due to the relatively long times required for complete setting up of same and due to the amount of osseous tissue to be necessarily removed by a surgeon in order to carry out installation of these types of implants.
It is to be added that the buried implant does not always find an appropriate response by the patient and that consequently possible problems may bring about further delay in the installation times and still more traumas on the concerned osseous tissue.
Beside the above described buried implants, a second typology of implants, known as xe2x80x9cTramontexe2x80x9d implants, has been available on the market since many years, said implants consisting of a single monolithic piece having a threaded anchoring portion intended for screw-fitting into the patient""s osseous tissue and a head portion intended for emerging from the gingival mucosa to constitute an attachment element for a tooth crown.
Typically, this type of implants requires accomplishment of holes of reduced diameters corresponding to the core of the threaded portion of the implant itself (about 2 mm) for anchoring to the patient""s osseous tissue.
Once drilling has been done as well as at least partial tapping of the hole, screwing down of the anchoring portion into the hole itself is carried out until the desired axial position is reached.
Since these types of implants, due to their own nature, are self-bearing and require holes of very reduced radial dimensions, on the one hand they are immediately operative and, on the other hand, they greatly reduce traumas to be borne by the patient.
While seen from the above standpoints xe2x80x9cTramontexe2x80x9d implants appear to be advantageous, they however have been found susceptible of improvements under different points of view.
In particular, xe2x80x9cTramontexe2x80x9d implants presently on the market have predetermined structures and sizes and require a great skill and experience by the installing surgeon, for personalizing the implant depending on the subject to be submitted to treatment and the anatomical features of the latter.
In addition, in presently available implants of the xe2x80x9cTramontexe2x80x9d type, the head portion emerging from the osseous tissue has a bulky conformation that hardly lends itself to enable easy installation of possible superstructures for arrangement of crowns and the like.
It is also to be noted that typically the surgeon, once he/she has carried cut installation of the implant, works on the head portion and suitably orients it depending on requirements.
This operation, if it is not carried out with appropriate care and skill, may involve breaking of the connecting neck between the head portion and the anchoring portion or at all events weakening of the connecting neck itself that during everyday use may be unable to withstand stresses transmitted to it.
It is apparent that in case of breakage of the connecting neck between the head portion and anchoring portion it is greatly problematic to carry out disengagement of the anchoring portion and therefore restoring of a new implant because the technical solutions presently available do not provide operating elements except those directly associated with the head portion.
After the above statements, the main object of the present invention is to provide a new dental endosseous implant capable of combining the positive aspects typical of xe2x80x9cTramontexe2x80x9d implants presently on the market with a greater flexibility in operation and capability of meeting the different anatomical requirements of a patient, without particular interventions and skill being called for by an installing surgeon.
It is a further object of the invention to provide a new implant which can be easily removed in case of breakage of the connecting neck between the head portion and anchoring portion of the implant itself.
Another important object of the invention is to provide an implant of easy structure and ready setting up, in which radial overall dimensions are reduced to a minimum with reference both to the head portion and the anchoring portion, without on the other hand impairing functionality and reliability of the implant itself.
The foregoing and further objects that will become more apparent in the course of the following description are substantially achieved by a dental endosseous implant comprising an anchoring portion intended for engagement in an osseous tissue of an upper jaw (or maxilla) or a lower jaw (or mandible); a head portion connected with the anchoring portion and adapted to emerge at least partly from said osseous tissue, said head portion being adapted to receive in engagement a superstructure.